A process for manufacturing a semiconductor device includes a cleaning process in which a semiconductor wafer is cleaned with a chemical liquid (cleaning liquid) and contaminant including particles, organic pollutants, and metal impurities attached to the semiconductor wafer and polymer after the etching process are removed.
A substrate cleaning apparatus performing such a cleaning process includes a single wafer cleaning apparatus which provides a processing liquid to a front surface and a back surface of the semiconductor wafer to perform the cleaning process, then performs a rinsing process according to the necessity, and rotates the semiconductor wafer at a high speed to perform a drying process.
As a method for efficiently removing the particles attached to the semiconductor wafer in such a single substrate cleaning apparatus, there is disclosed technology using two-fluid spray consisting of a chemical liquid and N2 gas (for example, see Japanese Laid-Open Patent Publication No. 2008-108830).
Further, in addition to the above-described method, there is disclosed a cleaning method using ultrasonic waves (for example, see Japanese Laid-Open Patent Publication No. 2005-64375).
Then, the pattern formed on the semiconductor wafer has recently become minute, and when cleaning the semiconductor wafer with the pattern, the damage, such as pattern collapse, may be easily incurred. That is, the damage, such as pattern collapse, may be incurred when trying to sufficiently remove the particles attached to the semiconductor wafer with the two-fluid spray. On the other hand, if the semiconductor wafer is cleaned within a power range generating no damage, such as the pattern collapse, the particles may be not sufficiently removed.